[gnome-calendar/mcatanzaro/#434-gnome-3-32] Don't leave dangling pointers in the GcalEvent cache

[Michael Catanzaro <mcatanzaro src gnome org>]

commit ad588e95adaff5e06841ac516621fd8d10757075
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Tue Jul 16 19:40:06 2019 -0500

    Don't leave dangling pointers in the GcalEvent cache
    
    The cache has an unowned pointer to the GcalEvent's UID. We need to
    update the cache with the GcalEvent's new UID to avoid use-after-free.
    
    Fixes #434

 src/gcal-event.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/src/gcal-event.c b/src/gcal-event.c
index e8eada98..3d8df82b 100644
--- a/src/gcal-event.c
+++ b/src/gcal-event.c
@@ -265,6 +265,9 @@ gcal_event_update_uid_internal (GcalEvent *self)
   id = e_cal_component_get_id (self->component);
 
   /* Clear the previous uid */
+  g_debug ("Removing '%s' (%p) from cache", self->uid, self);
+  g_hash_table_remove (event_cache, self->uid);
+
   g_clear_pointer (&self->uid, g_free);
 
   if (id->rid != NULL)
@@ -281,6 +284,9 @@ gcal_event_update_uid_internal (GcalEvent *self)
                                    id->uid);
     }
 
+  g_debug ("Adding %s to the cache", self->uid);
+  g_hash_table_insert (event_cache, self->uid, self);
+
   e_cal_component_free_id (id);
   g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_UID]);
 }